1. Field of the Invention
The present invention relates to an image processing system, an image processing method, and an image input system, having a function of discriminating whether an input image is a specific original image which should not be copied.
2. Description of the Related Art
Recently, a color image copying system of high performance has become popular, and with improvement in image quality of image input/output devices, it has become possible to take a faithful copy of an original image. On the other hand, it has become more and more important socially to prevent forgery of paper money and valuable securities by abusing such an image copying system. In view of this point, various inventions have been proposed in which at the time of digitally reading and copying a color original, a specific pattern contained in the read original image is identified, and when the pattern is judged to be a copy inhibit pattern such as paper money or a valuable security, the reproduction (copy output) of the image is stopped.
The related art will now be described with reference to FIG. 12, which is a block diagram showing a schematic configuration of a typical color copying system. In the same figure, the color copying system mainly comprises an image read unit 1201 which generates digital image signals of red (R), green (G) and blue (B) from an original image, an image output unit 1205 which reproduces a full-color image using colorants of yellow (Y), magenta (M), cyan (C) and black (K), and an image processing unit 1202 which produces YMCK image signals from the RGB image signals. In this color copying apparatus, every time the original is scanned in the image read unit 1201, signals for output are generated successively in the order of Y→M→C →K in the image processing unit 1202 and printing operation is performed in the image output unit 1205. Thus, copying of a full-color original is effected by scanning the original four times.
A copy inhibit original recognizing unit 1203 analyzes RGB signals outputted from the image read unit 1201 and judges whether a copy inhibit image such as paper money or a valuable security is included in the original image. The copy inhibit original recognizing unit 1203 performs processing for detecting a specific pattern in a copy inhibit original at the time of first and second scans of the original. An image working unit 1204 is for painting out an image signal with a preset specific value. If it is recognized in the copy inhibit original recognizing unit 1203 that a copy inhibit image is contained in the original image, the image signal is painted out with C and K which are the third and fourth printing colors, respectively. By adopting such a configuration, it becomes possible to prevent copying of copy inhibit matters such as paper money and valuable securities.
However, with the recent advance and spread of the digital/network technique, there is now an increasing tendency to constructing a color copying apparatus in a more systematized form, more particularly, in a form permitting not only copying of an original but also page editing. FIG. 13 is a block diagram showing a schematic configuration of a color image processing system which stores images page by page and which permits page editing such as gathering, stacking and composition. In addition to the configuration shown in FIG. 12, the color image processing system illustrated in FIG. 13 is provided with an image storing unit 1306 and an interface 1307 for the transmission and reception of image data to and from external devices connected to a network. The image read unit 1301, image processing unit 1302, copy inhibit original recognizing unit 1303, image working unit 1304, and image output unit 1305, are the same as in FIG. 12.
In connection with the color image processing system shown in FIG. 13, for example, it is here assumed that page editing is performed for 2up composition (outputting two pages of original images on one side of output paper) using plural sheets of originals. In this case, the reproduction of a copy inhibit original may be prevented by a method of preventing the copy of all the original images or a method of preventing the copy of only the original images judged to be copy inhibit images. The former method adopts the same configuration as in the related art and can thereby prevent the reproduction of a copy inhibit original, but is not preferred because the reproduction of images other than the copy inhibit images is also affected. The latter method prevents the reproduction of only a copy inhibit original, but to this end it is necessary to separately store information regarding in what page of original a copy inhibit image is contained, and perform image working responsive to the stored contents. As a result, there arises the problem that the system configuration and control become complicated.
In the color image processing system shown in FIG. 13, if the transmission and reception of image data are to be conducted via a network for example, even image data judged to be a copy inhibit data is transmitted as it is. As a result, it becomes possible for a destination color printer to reproduce the copy inhibit original and eventually an illegal forgery act becomes possible through the network.